The present invention relates to a silver halide photographic light-sensitive material and an image forming method using the light-sensitive material. Particularly, the present invention relates to a silver halide light-sensitive material that is used in the fields of graphic art, and to an image forming method to form a ultra-high contrast photographic image using the light-sensitive material.
The photomechanical process in the field of graphic arts includes a process of converting a photographic original image in continuous gradation to a dot image. In order to improve reproduction of the image, a technique of forming an ultra-high contrast image has been used.
Image formation systems capable of obtaining ultra-high contrast photographic properties through development with a processing solution having good storage stability are disclosed, for example, in U.S. Pat. Nos. 4,166,742, 4,168,977, 4,221,857, 4,224,401, 4,243,739, 4,272,606, and 4,311,781. These methods are a system of forming an ultra-high contrast image by processing a silver halide light-sensitive material, having incorporated therein a specific acylhydrazine compound, with a developing solution containing 0.15 mole/liter or more of a sulfuric acid salt preservative and having a pH ranging from 11.0 to 12.3.
In order to complete a high-contrast image formation using hydrazine derivatives, it is necessary to process with a developing solution having a pH of 11 or more, usually 11.5 or more.
However, developing solutions having a high pH value of pH 11 or more, even though they contain preservatives, are prone to air oxidation and are unstable. Therefore, such a developing solution needs a large amount of replenishment in order to maintain good photographic properties in running use over a long period of time. An image formation system capable of obtaining an ultra-high contrast image, even in a processing with a developing solution having a pH of less than 11, in order to compensate for such a defect, is disclosed as described below. For example, the development of hydrazine derivatives capable of minimizing the variation width of photographic properties ascribable to the change in the pH of the developing solution, the use of a nucleation development accelerator for acceleration of hard gradation enhancement, or the like is attempted, to achieve such an image formation system.
For example, JP-A-62-222241 (the term xe2x80x9cJP-A-xe2x80x9d as used herein means an unexamined published Japanese patent application), JP-A-62-250439, JP-A-62-280733, and the like disclose nucleation accelerators for acceleration of hard gradation enhancement. A high-contrast image showing a certain level of photographic properties can indeed be attained by incorporating these nucleation accelerators, in combination with a specific hydrazine derivative, in a light-sensitive material. However, light-sensitive materials prepared by such a previous method are not fully satisfactory, in view of deterioration of dot image quality, because they cause a sand-like or spot-like fogging, so-called xe2x80x9cblack spots,xe2x80x9d which are made of fine developed silver, at the non-image portion that is not exposed.
The black spots are apt to occur when, particularly by aerial oxidation of a developing solution, a rise in pH of the solution, and/or a reduction in the concentration of sulfuric acid therein, is caused.
JP-A-1-179939 and JP-A-1-179940 describe a method of processing a light-sensitive material containing a nucleation development accelerator having a group adsorptive onto silver halide emulsion particles and a nucleating agent having the same adsorptive group, with a developing solution having a pH of 11 or less. U.S. Pat. No. 4,975,354 discloses that an effect on acceleration of hard gradation enhancement can be attained by processing a light-sensitive material containing a secondary or tertiary amine compound having a repeating unit of ethylene oxide in combination with a hydrazine compound, with a developing solution having a pH of 11.4.
JP-A-6-242534 discloses a method of forming a high-contrast image that shows a gamma value of 10 or more, by processing a light-sensitive material containing a bis-type heterocyclic N-quaternary onium salt and a hydrazine compound, with a developing solution having a pH of 11 or less.
Further, JP-A-10-90841 describes bispyridinium salt development accelerators in which pyridinium moieties are connected via an alkylene group. However, it is also difficult to obtain satisfactory high-contrast photographic properties by using these compounds with a developing solution having a low pH in particular. Further, JP-A-10-90841 and JP-A-10-39444 disclose bispyridinium salt and bis-isoquinolinium salts, each of which has a recurring unit of 4 to 18 ethyleneoxy groups. However, the compounds disclosed therein fail to reach a satisfactory level, even though somewhat high-contrast photographic properties can be attained thereby.
Accordingly, a first object of the present invention is to provide a silver halide photographic light-sensitive material that has improved photographic properties. A secondary object of the present invention is to provide a silver halide photographic light-sensitive material that is capable of obtaining photographic properties of high-contrast negative gradation having a gamma (xcex3) value exceeding 10, by the use of a stable developing solution, and further that is excellent in image quality. A third object of the present invention is to provide a silver halide photographic light-sensitive material that is excellent in reproducibility of an original. A fourth object of the present invention is to provide a silver halide photographic light-sensitive material showing, in addition to the foregoing, less variation in sensitivity, xcex3 value, and Dmax, without increasing black spots, even though the light-sensitive material is processed with a developing solution in which the concentration of sulfurous acid preservative has been reduced, or in which the pH value has been changed, due to fatigue over time, or a developing solution in which the pH value has been changed and/or the bromide ion concentration has been increased by processing a large amount of films. Further, a fifth object of the present invention is to provide a processing method of a silver halide photographic light-sensitive material, which method is capable of obtaining a negative image having an ultrahigh contrast and improved photographic properties, by use of a developing solution having a lower pH than the previous pH which has been used in the past.
Other and further objects, features, and advantages of the invention will appear more fully from the following description.
The foregoing objects of the present invention have been achieved with the following constructions of (1) to (7).
(1) A silver halide photographic light-sensitive material comprising at least a light-sensitive silver halide emulsion layer applied on a support, wherein said emulsion layer or another hydrophilic colloidal layer comprises at least one kind of compounds selected from a group consisting of a quaternary nitrogen or phosphorus salt compound, having 20 or more of total recurring units consisting of an ethyleneoxy group and/or a propyleneoxy group in a molecule; a quaternary salt compound represented by the following formula (A); and a quaternary salt compound represented by the following formula (B): 
wherein Q represents a nitrogen atom or a phosphorus atom, R1, R2 and R3 each independently represent an alkyl group, an aryl group, an alkenyl group, an alkynyl group, or a heterocyclic group, L1 represents an alkylene group, Y represents xe2x80x94C(xe2x95x90O) or xe2x80x94SO2xe2x80x94, L2 represents a divalent connecting group having at least one hydrophilic group, Xnxe2x88x92 represents an n-valent counter anion, and n represents an integer of 1 to 3, provided that Xnxe2x88x92 can be omitted when another anionic group exists in a molecule and forms an intramolecular salt with P+ or a quaternary nitrogen atom, 
wherein A represents an organic moiety necessary to complete a nitrogen-containing aromatic heterocyclic ring, provided that the nitrogen-containing aromatic heterocyclic ring formed by A may have a substituent, but the substituent having thereon a primary hydroxyl group is excluded. L1, Y, L2 and Xnxe2x88x92 each have the same meanings as those of the formula (A).
(2) The silver halide photographic light-sensitive material as described in (1), wherein the nitrogen-containing aromatic heterocyclic ring formed by A in the quaternary salt compound represented by formula (B) is 4-phenylpyridine, quinoline or isoquinoline.
(3) The silver halide photographic light-sensitive material as described in (1), wherein the quaternary nitrogen or phosphorus salt compound having the total of 20 or more recurring units consisting of an ethyleneoxy group and/or a propyleneoxy group in a molecule, is represented by any one of the following formulae (I) to (IV): 
in formula (I), Q represents a nitrogen atom or a phosphorus atom, R10, R11 and R12 each represent an aliphatic group, an aromatic group, or a heterocyclic group, these groups may combine with each other to form a ring structure, M represents an m-valent organic group in which a carbon atom bonds to Q+, m represents an integer of 1 to 4;
in formulae (II), (III) and (IV), A1, A2, A3, A4 and A5 each represent an organic moiety necessary to complete a quaternary nitrogen-containing unsaturated heterocyclic ring, L1 and L2 each represent a divalent connecting group, R1, R2 and R3 each independently represent a substituent;
in formulae (I), (II), (III) and (IV), Xnxe2x88x92 represents an n-valent counter anion, n represents an integer of 1 to 3, provided that Xnxe2x88x92 can be omitted when another anionic group exists in a molecule and forms an intramolecular salt with Q+ or a quaternary nitrogen atom;
the quaternary salts represented by formulae (I), (II), (III) and (IV) each have 20 or more of total recurring units consisting of an ethyleneoxy group and/or a propyleneoxy group in each of their molecules, said recurring units may be present at plural portions in the molecule.
(4) The silver halide photographic light-sensitive material as described in (3), wherein the quaternary salt compound is a compound represented by the formula (II) or (III).
(5) The silver halide photographic light-sensitive material as described in any one of (1) to (4), wherein said silver halide emulsion layer comprises at least one kind of hydrazine derivatives.
(6) The silver halide photographic light-sensitive material as described in (5), wherein a second silver halide emulsion layer which is different from the first silver halide emulsion layer containing the hydrazine derivatives, or another hydrophilic colloidal layer, comprise a redox compound capable of releasing a development inhibitor by oxidization.
(7) A processing method of a silver halide photographic light-sensitive material, which comprises processing the silver halide photographic light-sensitive material as described in any one of (1) to (6) with a developing solution having a pH of less than 11.0, thereby forming an ultrahigh contrast negative image.
The quaternary salt compounds for use in the present invention are described in detail below.
Examples of the aliphatic groups represented by R10, R11 and R12 in the formula (I) include straight-chain or branched alkyl groups such as a methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, octyl group, 2-ethylhexyl group, dodecyl group, hexadecyl group and octadecyl group; aralkyl groups such as a substituted or unsubstituted benzyl group; cycloalkyl groups such as a cyclopropyl group, cyclopentyl group and cyclohexyl group; alkenyl groups such as an aryl group, vinyl group and 5-hexenyl group; cycloalkenyl groups such as a cyclopentenyl group and cyclohexenyl group; and alkynyl groups such as a phenylethynyl group. Examples of the aromatic group include aryl groups such as a phenyl group, naphthyl group and phenanthryl group. Examples of the heterocyclic group include a pyridyl group, quinolyl group, furyl group, imidazolyl group, thiazolyl group, thiadiazolyl group, benzotriazolyl group, benzothiazolyl group, morpholyl group, pyrimidyl group and pyrrolidyl group.
Examples of the substituent substituted on these groups include the groups represented by R10, R11 and R12, halogen atoms (such as a fluorine atom, chlorine atom, bromine atom and iodine atom), nitro groups, (alkyl or aryl)amino groups, alkoxy groups, aryloxy groups, (alkyl or aryl)thio groups, carbonamide groups, carbamoyl groups, ureido groups, thioureido groups, sulfonylureido groups, sulfonamide groups, sulfamoyl groups, hydroxyl groups, sulfonyl groups, carboxyl groups (including carboxylato groups), sulfo groups (including sulfonato groups), cyano groups, oxycarbonyl groups, acyl groups, and heterocyclic groups (including heterocyclic groups containing a quaternary nitrogen atom). These substituents may be further substituted with these substituents.
The groups represented by R10, R11 and R12 of the formula (I) may be combined with each other to form a cyclic structure.
Examples of the group represented by M in the formula (I) include groups having the same meanings as R10, R11 or R12 when m represents 1. When m represents an integer of 2 or more, M represents a connecting group with m valences which connects to Q+ by a carbon atom contained in M. Specifically, M represents an m-valent connecting groups which are formed by combining groups such as an alkylene group, arylene group, heterocyclic group, with a xe2x80x94COxe2x80x94 group, xe2x80x94Oxe2x80x94 group, xe2x80x94N(RN)xe2x80x94 group, xe2x80x94Sxe2x80x94 group, xe2x80x94SOxe2x80x94 group, xe2x80x94SO2xe2x80x94 group, or xe2x80x94Pxe2x95x90Oxe2x80x94 group (RN represents a hydrogen atom or a group having the same meaning as R10, R11 or R12. When plural RNS are present in a molecule, they may be the same or different and further they may be combined with each other). M may have an optional substituent. Examples of the optional substituent include the same substituents as those which the group represented by R10, R11 or R12 may have.
In the formula (I), R10, R11 and R12 are preferably groups having 20 or less carbon atoms. When Q represents a phosphorous atom, R10, R11 and R12 are particularly preferably aryl groups having 15 or less carbon atoms. When Q represents a nitrogen atom, they are particularly preferably alkyl, aralkyl, or aryl groups, having 15 or less carbon atoms. Preferably, m is 1 or 2. When m represents 1, M is preferably a group having 20 or less carbon atoms and particularly preferably an alkyl, aralkyl or aryl group, having a total carbon number of 15 or less. When m represents 2, the divalent organic group represented by M is preferably an alkylene group, arylene group, or a divalent group which is formed by combining these groups with a xe2x80x94COxe2x80x94 group, xe2x80x94Oxe2x80x94 group, xe2x80x94N(RN)xe2x80x94 group, xe2x80x94Sxe2x80x94 group, or SO2xe2x80x94 group (RN is the same meanings as the above RN) . When m represents 2, M is preferably a divalent group that connects to Q+ by a carbon atom contained in M and that has a total carbon number of 20 or less. In addition, the preferable range of the total carbon number is not limited to the above range, when M, or R10, R11 or R12 contains plural repeating units of an ethyleneoxy group or propyleneoxy group. Also, when m represents an integer of 2 or more, R10, R11 and R12 are each present in plural in a molecule. In this case, these plural R10s, R11s or R12s may be the same or different respectively.
The quaternary salt compound represented by the formula (I) has 20 or more repeating units of an ethyleneoxy or propyleneoxy group in total in its molecule. These repeating units either may be substituted on one position or may be substituted so as to extend over plural positions. When m represents an integer of 2 or more, more preferably the connecting group represented by M has 20 or more repeating units of an ethyleneoxy or propyleneoxy group.
In the formula (II) or (III) , A1, A2, A3, and A4 respectively represent an organic moiety necessary to form a substituted or unsubstituted unsaturated heterocyclic ring that contains a quaternary nitrogen atom. The organic moiety may contain a carbon atom, oxygen atom, nitrogen atom, sulfur atom, and hydrogen atom. The heterocyclic ring may be further condensed with a benzene ring.
Examples of the unsaturated hetero ring formed by A1, A2, A3 and A4 include a pyridine ring, quinoline ring, isoquinoline ring, imidazole ring, thiazole ring, thiadiazole ring, benzotriazole ring, benzothiazole ring, pyrimidine ring and pyrazole ring. A pyridine ring, a quinoline ring, and an isoquinoline ring are particularly preferable.
The unsaturated hetero ring which A1, A2, A3 and A4 form in combination with a quaternary nitrogen atom may have a substituent. Examples of the substituent in this case include the same substituents as those which the group represented by R10, R11 or R12 may have. Preferable examples of the substituent include halogen atoms (particularly a chlorine atom); and aryl groups, (preferably a phenyl group), alkyl groups, carbamoyl groups, (alkyl or aryl) amino groups, oxycarbonyl groups, alkoxy groups, aryloxy groups, (alkyl or aryl)thio groups, hydroxy groups, carbonamide groups, sulfonamide groups, sulfo groups (including sulfonato groups), and carboxyl groups (including carboxylato groups), which have 20 or less carbon atoms. Particularly preferable examples include phenyl groups, alkylamino groups, carbonamide groups and a chlorine atom and most preferable examples include phenyl groups. Specifically, in the formula (II), the most preferable heterocylic groups which A1 and A2 form are 4-phenylpyridine.
The divalent connecting groups represented by L1 or L2 are preferably those constituted by singly, an alkylene group, arylene group, alkenylene group, alkynylene group, divalent heterocyclic group, xe2x80x94SO2xe2x80x94, xe2x80x94SOxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94N(RNxe2x80x2)xe2x80x94 (wherein RNxe2x80x2 represents an alkyl group, aralkyl group, aryl group, or hydrogen atom), xe2x80x94C(xe2x95x90O)xe2x80x94, or xe2x80x94P(xe2x95x90O)xe2x80x94 ; or by a combination of these groups. The divalent connecting groups represented by L1 or L2 may have an optional substituent. Examples of the substituent include the same substituents as those which the group represented by R10, R11 or R12 may have. Particularly preferable examples of L1 or L2 include those constituted by singly, the alkylene group, the arylene group, xe2x80x94C(xe2x95x90O)xe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SO2 or xe2x80x94N(RNxe2x80x2), or by a combination of these groups.
R1 or R2 is preferably an alkyl or aralkyl group, having 1 to 20 carbon atoms, and R1 and R2 may be the same or different. R1 or R2 may have a substituent. Examples of the substituent include the same substituents as those which the group represented by R10, R11 or R12 may have. Particularly preferably, R1 and R2 respectively are an alkyl or aralkyl group, having 1 to 10 carbon atoms. Preferable examples of the substituent include carbamoyl groups, oxycarbonyl groups, acyl groups, aryl groups, sulfo groups (including sulfonato groups), carboxyl groups (including carboxylato groups), hydroxy groups, (alkyl or aryl)amino groups, and alkoxy groups.
In addition, the preferrable range of the total carbon number is not limited to the above range, when R1 or R2 contains plural repeating units of an ethyleneoxy group or propyleneoxy group.
The quaternary salt compound represented by the formula (II) or (III) has 20 or more repeating units of an ethyleneoxy or propyleneoxy group in total in its molecule. Although these repeating units may be substituted either on one position or on plural positions and may also be substituted on any of A1, A2, A3, A4, R1, R2, L1 and L2, preferably the connecting group represented by L1 or L2 has a total of 20 or more repeating units of an ethyleneoxy or propyleneoxy group.
In formula (IV), A5 represents an organic moiety capable of forming an unsaturated heterocyclic ring with a quaternary nitrogen atom. R3 represents a substituent.
The nitrogen-containing unsaturated ring composed of A5 may contain a carbon atom, a hydrogen atom, an oxygen atom, or a sulfur atom, in addition to the nitrogen atom, may be further condensed with a benzene ring, further may have a substituent. Examples of the hetero ring include the same as those of the nitrogen-containing unsaturated ring composed of A1, A2, A3, or A4 of formulae (II) and (III). The preferred range is also the same. Among them, pyridine, quinoline and isoquinoline rings are specifically preferred.
When the nitrogen-containing unsaturated ring composed of A5 has a substituent, examples of the substituent is the same as the substituent which the nitrogen-containing unsaturated ring composed of A1, A2, A3 or A4 of formulae (II) and (III) may have. The preferred range is also the same.
Preferably, R3 represents an alkyl group or an aralkyl group, which may be unsubstituted or substituted with a substituent, and straight-chain, branched, or cyclic. Examples of the foregoing substituent are the same as the substituent that the groups represented by R1 and R2 of formula (III) may have. The preferred range is also the same. Among them, especially preferred are a carbamoyl group, an oxycarbonyl group, an acyl group, an aryl group, a sulfo group including sulfonato, a carboxyl group including carboxylato, an (alkyl or aryl)amino group, and an alkoxy group.
The quaternary salt compound represented by the formula (IV) has a total of 20 or more repeating units of an ethyleneoxy or propyleneoxy group in its molecule. Although these repeating units may be substituted either on one position or on plural positions and may also be substituted on any of A5 and R3, preferably the group represented by R3 has a total of 20 or more repeating units of an ethyleneoxy or propyleneoxy group.
In the formula (I), (II), (III) and (IV), Xnxe2x88x92 is a counter anion that has a negative charge capable of neutralizing a positive charge existing on the quaternary salt. n represents an integer of 1 to 3. Xnxe2x88x92 may be an inorganic acid ion or an organic acid ion. As the inorganic acid ion, halide ions such as a chloride ion and a bromide ion, a sulfuric acid ion, a phosphoric acid ion, a nitric acid ion, or the like can be used. As the organic acid ion, carboxylate ions such as an acetate ion, oxalate ion, fumarate ion and benzoate ion, sulfo ions such as a methane sulfonic acid ion, a p-toluene sulfonate, a naphthalene disulfonic acid ion, or the like can be used.
As the counter anion represented by Xnxe2x88x92, a halide ion, carboxylate ion, sulfo ion or sulfuric acid ion is preferable. Preferably n is 1 or 2. As Xnxe2x88x92, a chloride ion or bromide ion is particularly preferable and a chloride ion is most preferable.
However, Xnxe2x88x92 can be omitted when another anionic group exists in a molecule and forms an intramolecular salt with P+ or a quaternary nitrogen atom.
The quaternary salt compounds represented by the formulae (I), (II), (III) and (IV) may include an ethyleneoxy group and a propyleneoxy group repeatedly at the same time. In the case of including plural repeating units of an ethyleneoxy or propyleneoxy group, the number of repetitions may be given either by taking one value strictly or as an average. In the latter case, the quaternary salt compound is a mixture having a certain degree of distribution of molecular weight.
In the present invention, the case of having a total of 20 or more repeating units of an ethyleneoxy group is more preferable and the case of having 20 to 67 repeating units of an ethyleneoxy group in total is most preferable.
In the present invention, among quaternary salts represented by formulae (I), (II), (III) and (IV), those represented by formulae (II) or (III) are preferred. Among them, those represented by formula (II) are more preferred. In formula (II), it is preferable that a connecting group represented by L1 has 20 or more of recurring units of the ethyleneoxy group. Further, it is most preferable that a connecting group represented by L1 has from 30 to 67 in total of recurring units of the ethyleneoxy group. If the total number of the recurring units exceed the above range, a synthesis of the compound will become complicated.
Next, specific examples of the quaternary salt compounds for use in the present invention will be shown (in the following formulae, Me, Bu, and Ph each represents methyl, butyl, and phenyl groups, respectively.). The present invention is not limited by the following compound examples. 